[part 1/n] Introduce vtable-based dispatch

userspace/libscap/CMakeLists.txt

@@ -81,17 +81,13 @@ list(APPEND targetfiles
 	syscall_info_table.c
 	../../driver/dynamic_params_table.c
 	../../driver/event_table.c
-	../../driver/flags_table.c)
-
-if(NOT APPLE)
-	list(APPEND targetfiles
-		scap_udig.c)
-endif()
-
+	../../driver/flags_table.c
+	ringbuffer/devset.c)
 
 if(CMAKE_SYSTEM_NAME MATCHES "Linux")
 	list(APPEND targetfiles
 		scap_bpf.c
+		scap_kmod.c
 		../../driver/syscall_table.c
 		../../driver/fillers_table.c)
 
@@ -117,8 +113,7 @@ if (CMAKE_SYSTEM_NAME MATCHES "SunOS")
 		socket nsl)
 elseif (CMAKE_SYSTEM_NAME MATCHES "Linux")
 	target_link_libraries(scap
-		elf
-		rt)
+		elf)
 elseif (WIN32)
 	target_link_libraries(scap
 		Ws2_32.lib)
@@ -163,3 +158,28 @@ if(CREATE_TEST_TARGETS AND NOT WIN32)
 		# Add unit test directories
 		add_subdirectory(test)
 endif()
+
+if(CMAKE_SYSTEM_NAME MATCHES "Linux")
+	add_subdirectory(linux)
+	include_directories(linux)
+elseif(WIN32)
+	add_subdirectory(win32)
+	include_directories(win32)
+endif()
+
+add_definitions(-DHAS_ENGINE_NOOP)
+add_subdirectory(engine/noop)
+# don't link the noop engine to libscap directly,
+# it's a helper library for other engines (it's completely useless on its own)
+
+add_definitions(-DHAS_ENGINE_NODRIVER)
+add_subdirectory(engine/nodriver)
+target_link_libraries(scap scap_engine_nodriver)
+
+add_definitions(-DHAS_ENGINE_SOURCE_PLUGIN)
+add_subdirectory(engine/source_plugin)
+target_link_libraries(scap scap_engine_source_plugin)
+
+add_definitions(-DHAS_ENGINE_UDIG)
+add_subdirectory(engine/udig)
+target_link_libraries(scap scap_engine_udig)

userspace/libscap/engine/nodriver/CMakeLists.txt

@@ -0,0 +1,3 @@
+include_directories(${LIBSCAP_INCLUDE_DIRS} ../noop)
+add_library(scap_engine_nodriver nodriver.c)
+target_link_libraries(scap_engine_nodriver scap_engine_noop)

userspace/libscap/engine/nodriver/nodriver.c

@@ -0,0 +1,71 @@
+/*
+Copyright (C) 2022 The Falco Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "nodriver.h"
+#include "noop.h"
+
+#include "scap.h"
+#include "scap-int.h"
+#include "../common/strlcpy.h"
+#include "gettimeofday.h"
+#include "sleep.h"
+
+static struct nodriver_engine* alloc_handle(scap_t* main_handle, char* lasterr_ptr)
+{
+	struct nodriver_engine *engine = calloc(1, sizeof(struct nodriver_engine));
+	if(engine)
+	{
+		engine->m_lasterr = lasterr_ptr;
+	}
+	return engine;
+}
+
+static int32_t next(struct scap_engine_handle handle, scap_evt** pevent, uint16_t* pcpuid)
+{
+	static scap_evt evt;
+	evt.len = 0;
+	evt.tid = -1;
+	evt.type = PPME_SCAPEVENT_X;
+	evt.nparams = 0;
+
+	sleep_ms(100);
+
+	evt.ts = get_timestamp_ns();
+	*pevent = &evt;
+	return SCAP_SUCCESS;
+}
+
+const struct scap_vtable scap_nodriver_engine = {
+	.name = "nodriver",
+	.mode = SCAP_MODE_NODRIVER,
+
+	.alloc_handle = alloc_handle,
+	.init = NULL,
+	.free_handle = noop_free_handle,
+	.close = noop_close_engine,
+	.next = next,
+	.start_capture = noop_start_capture,
+	.stop_capture = noop_stop_capture,
+	.configure = noop_configure,
+	.get_stats = noop_get_stats,
+	.get_n_tracepoint_hit = noop_get_n_tracepoint_hit,
+	.get_n_devs = noop_get_n_devs,
+	.get_max_buf_used = noop_get_max_buf_used,
+};

userspace/libscap/engine/nodriver/nodriver.h

@@ -0,0 +1,28 @@
+/*
+Copyright (C) 2022 The Falco Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+*/
+#pragma once
+
+#include <stdint.h>
+
+struct scap;
+
+struct nodriver_engine
+{
+	char* m_lasterr;
+};
+
+#define SCAP_HANDLE_T struct nodriver_engine

userspace/libscap/engine/noop/CMakeLists.txt

@@ -0,0 +1,2 @@
+include_directories(${LIBSCAP_INCLUDE_DIRS})
+add_library(scap_engine_noop noop.c)

userspace/libscap/engine/noop/noop.c

@@ -0,0 +1,121 @@
+/*
+Copyright (C) 2022 The Falco Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+struct noop_engine
+{
+	char *m_lasterr;
+};
+
+#define SCAP_HANDLE_T struct noop_engine
+
+#include "noop.h"
+#include "scap.h"
+#include "scap-int.h"
+#include "../common/strlcpy.h"
+
+struct noop_engine* noop_alloc_handle(scap_t* main_handle, char* lasterr_ptr)
+{
+	struct noop_engine *engine = calloc(1, sizeof(struct noop_engine));
+	if(engine)
+	{
+		engine->m_lasterr = lasterr_ptr;
+	}
+	return engine;
+}
+
+void noop_free_handle(struct scap_engine_handle engine)
+{
+	free(engine.m_handle);
+}
+
+int noop_close_engine(struct scap_engine_handle engine)
+{
+	return SCAP_SUCCESS;
+}
+
+int32_t noop_next(struct scap_engine_handle handle, scap_evt** pevent, uint16_t* pcpuid)
+{
+	return SCAP_EOF;
+}
+
+int32_t noop_start_capture(struct scap_engine_handle engine)
+{
+	return SCAP_SUCCESS;
+}
+
+int32_t noop_stop_capture(struct scap_engine_handle engine)
+{
+	return SCAP_SUCCESS;
+}
+
+int32_t unimplemented_op(char* err, size_t err_size)
+{
+	strlcpy(err, "Operation not implemented", err_size);
+	return SCAP_FAILURE;
+}
+
+int32_t noop_configure(struct scap_engine_handle engine, enum scap_setting setting, unsigned long arg1, unsigned long arg2)
+{
+	// the open path disables dropping mode so report success even if we
+	// don't really support it
+	if(setting == SCAP_SAMPLING_RATIO && arg2 == 0)
+	{
+		return SCAP_SUCCESS;
+	}
+	return unimplemented_op(engine.m_handle->m_lasterr, SCAP_LASTERR_SIZE);
+}
+
+int32_t noop_get_stats(struct scap_engine_handle engine, scap_stats* stats)
+{
+	return SCAP_SUCCESS;
+}
+
+int32_t noop_get_n_tracepoint_hit(struct scap_engine_handle engine, long* ret)
+{
+	return SCAP_NOT_SUPPORTED;
+}
+
+uint32_t noop_get_n_devs(struct scap_engine_handle engine)
+{
+	return 0;
+}
+
+uint64_t noop_get_max_buf_used(struct scap_engine_handle engine)
+{
+	return 0;
+}
+
+const struct scap_vtable scap_noop_engine = {
+	.name = "noop",
+	.mode = SCAP_MODE_NODRIVER,
+
+	.alloc_handle = noop_alloc_handle,
+	.init = NULL,
+	.free_handle = noop_free_handle,
+	.close = noop_close_engine,
+	.next = noop_next,
+	.start_capture = noop_start_capture,
+	.stop_capture = noop_stop_capture,
+	.configure = noop_configure,
+	.get_stats = noop_get_stats,
+	.get_n_tracepoint_hit = noop_get_n_tracepoint_hit,
+	.get_n_devs = noop_get_n_devs,
+	.get_max_buf_used = noop_get_max_buf_used,
+};

userspace/libscap/engine/noop/noop.h

@@ -0,0 +1,40 @@
+/*
+Copyright (C) 2022 The Falco Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+*/
+
+#pragma once
+
+#include "engine_handle.h"
+#include "scap_vtable.h"
+
+typedef struct scap scap_t;
+typedef struct ppm_evt_hdr scap_evt;
+typedef struct scap_stats scap_stats;
+
+struct noop_engine* noop_alloc_handle(scap_t* main_handle, char* lasterr_ptr);
+void noop_free_handle(struct scap_engine_handle engine);
+int noop_close_engine(struct scap_engine_handle engine);
+int32_t noop_next(struct scap_engine_handle handle, scap_evt** pevent, uint16_t* pcpuid);
+int32_t noop_start_capture(struct scap_engine_handle engine);
+int32_t noop_stop_capture(struct scap_engine_handle engine);
+int32_t unimplemented_op(char* err, size_t err_size);
+int32_t noop_configure(struct scap_engine_handle engine, enum scap_setting setting, unsigned long arg1, unsigned long arg2);
+int32_t noop_get_stats(struct scap_engine_handle engine, scap_stats* stats);
+int32_t noop_get_n_tracepoint_hit(struct scap_engine_handle engine, long* ret);
+uint32_t noop_get_n_devs(struct scap_engine_handle engine);
+uint64_t noop_get_max_buf_used(struct scap_engine_handle engine);
+
+extern const struct scap_vtable scap_noop_engine;

userspace/libscap/engine/source_plugin/CMakeLists.txt

@@ -0,0 +1,3 @@
+include_directories(${LIBSCAP_INCLUDE_DIRS} ../noop)
+add_library(scap_engine_source_plugin source_plugin.c)
+target_link_libraries(scap_engine_source_plugin scap_engine_noop)